While digital computers are capable of extremely rapid operation, delays are inherent in the input and output functions pertaining to picture processing, namely the digitizing of pictorial information, introducing it into a digital computer, and obtaining a suitable output after processing has been completed. These delays are compounded by the need for piecewise operation since no inner computer memory is capable of storing intensity data pertaining 1 .times. 10.sup.6 picture points, which constitute only a moderate sized picture.
To obviate these difficulties, parallel or near-parallel optoelectronic analog TV-type processing techniques have been devised as in the instant invention. The input information is imparted to a light beam by conventional optical means but is processed optelectronically, and the output is electronic. The storage image tube, invented by Knoll and described in U.S. Pat. No. 2,856,559 (June 1952) was developed primarily by ITT and described in the ITT Technical Note 103 by E. H. Ebehardt, Sept. 21 (1967). This tube has been a preferred device for analog central processor. Its principle of operation has been analyzed by Hawkins and Munsey as described in Proc. IEEE 55 1084 (1967) and Journal Optical Soc. 57, 914 (1967), and a system successfully using it in specialized applications has been developed by Goodyear under the trade mark of CORRELATRON described in a paper presented at NAECON Conference, May 6-8 (1968) in Dayton, Ohio. The storage image tube can be used for a number of simple processing operations, not complex ones, such as Fourier Transforms. For general purpose image processing it is advantageous to employ systems for parallel processing, based on the use of display devices, suitable for complex operations as well as faster and more precise. This invention describes a system which accomplishes this objective and is of special interest in application to topographic sciences.